In the coking processes, hot organic vapors are quenched by spraying the vapors with aqueous liquids, including water, called flushing liquor. In addition to quenching, the flushing liquor provides a carrying medium for the tars and other contaminants formed in the coking process. The contaminants include ammonia and hydrophobic compounds, such as coke powder and coal powder.
Coke and coal powders, however, frequently act as emulsifiers and form water in oil (W/O) emulsions in tar, or oil and water (O/W) emulsions in flushing liquor. If the tar/flushing liquor emulsion is not resolved, the emulsified particles will clog the spray nozzles when the flushing liquor is recycled through the coking process. Clogged nozzles may cause severe heating problems resulting in a failure of the coke process.
In the past decade, Coal Moisture Control (CMC) technology and applications have been researched and implemented in many countries to reduce energy consumption. The decrease in coal moisture, however, results in more coke and coal powders in the flushing liquor, thus increasing emulsification as compared to traditional coking processes. Thus, as the push towards energy reduction and CMC technology increases, there is an ever increasing need for demulsifying tar/flushing liquor emulsions.